Summary:

Agricultural intensification has led to dramatic decreases of birds living on farmland. Some species, like the Skylark, have decreased by 95% since the 1960s. To help these species, farmers are financially stimulated to sow flowers and grasses in the margins of their fields. These field margins contain up to five times as much insects as regular crops. Skylarks highly prefer field margins to search food for their young. Yet, the presence of field margins did not improve the body weight of the young. Also their survival was not improved. The main cause of nest loss was not food shortage, but agricultural operations and predation. In particular the frequent mowing of grassland caused high nest losses. In order to protect the Skylark and similar bird species, it is important to develop new, whole-field management options that provide a safe nesting environment. This can be realised by postponed mowing of grassland or the growth of low-intensity crops like lucerne. In general, the effectiveness of bird protection on Dutch arable farmland would increase when the management was better targeted to solve species-specific bottlenecks, instead of offering general measures only.